#network engineer

Smagu prisiminti, kiek darbo ir mėnesių reikėjo įdėti į savo mokslus ir karjerą. Buvo sunku, bet dabar chillinu.

I’ve been interested with learning the more intricate details of docker and server setups. This is mostly due to me being the guy setting up gaming servers for my gaming buddies.

DVTI LAB Topology

Today I have configured a practice DVTI setup. The routing used was OSPF, there are static routes on the PC1 and PC2 devices. Remember to enable redistribution for static.

See below configuration for R1 the server and R2 the Remote client as per above Topology.

R1(config)#crypto isakmp policy 1 R1(config-isakmp)#authentication pre-share R1(config-isakmp)#encryption 3des R1(config-isakmp)#hash sh R1(config-isakmp)#group 2 R1(config-isakmp)#exit R1(config)# R1(config)#crypto isakmp client configuration group admin R1(config-isakmp-group)#key admin R1(config-isakmp-group)#pool admin R1(config-isakmp-group)#acl stacl R1(config-isakmp-group)#exit R1(config)# R1(config)#ip local pool admin 192.168.100.100 192.168.100.254 R1(config)# R1(config)#ip access-list extended stacl R1(config-ext-nacl)#permit ip 192.168.101.0 0.0.0.255 any R1(config-ext-nacl)#exit R1(config)# R1(config)#crypto isakmp profile isakmp_pro R1(conf-isa-prof)#match identity group admin R1(conf-isa-prof)#client configuration address respond R1(conf-isa-prof)#client authentication list default R1(conf-isa-prof)#isakmp authorization list default R1(conf-isa-prof)#virtual-template 1 R1(conf-isa-prof)#exit R1(config)# R1(config)#crypto ipsec transform-set ez esp-3des esp-sha-hmac R1(cfg-crypto-trans)#mode tunnel R1(cfg-crypto-trans)#exit R1(config)# R1(config)#crypto ipsec profile cisco R1(ipsec-profile)#set transform-set ez R1(ipsec-profile)#set isakmp-profile isakmp_pro R1(ipsec-profile)#exit R1(config)#interface virtual-template 1 type tunnel R1(config-if)#ip unnumbered serial 0/0 R1(config-if)#tunnel source serial 0/0 R1(config-if)#tunnel mode ipsec ipv4 R1(config-if)#tunnel protection ipsec profile cisco %CRYPTO-6-ISAKMP_ON_OFF: ISAKMP is ON R1(config-if)#exit R1(config)#aaa new-model R1(config)#aaa authentication login default local R1(config)#aaa authorization network default local R1(config)#username cisco privilege 15 secret cisco

R2(config)# R2(config)#crypto ipsec client ezvpn ccc

R2(config-crypto-ezvpn)#username cisco password cisco R2(config-crypto-ezvpn)#mode client R2(config-crypto-ezvpn)#peer 101.1.1.100 R2(config-crypto-ezvpn)#group admin key admin R2(config-crypto-ezvpn)#connect auto R2(config-crypto-ezvpn)#int f0/0 R2(config-if)#crypto ipsec client ezvpn ccc inside R2(config-if)#int s0/1 R2(config-if)#crypto ipsec client ezvpn ccc outside R2(config-if)# *Mar  1 00:36:23.671: %CRYPTO-6-ISAKMP_ON_OFF: ISAKMP is ON

A Request to enter in the command (crypto ipsec client ezvpn xauth) will be generated. You will then be prompted for username and password this will be cisco and cisco as per my configuration above.

The configuration will now be completed.

In today’s world, Computer networking plays a vital role in the IT industry. If the computer networks stop working for a short period, many tasks can be disrupted. Basic knowledge of networking is essential, as devices rely on a set of communication protocols to exchange data over wired and wireless connections. Understanding networking fundamentals can open up various career opportunities in the IT sector.

What is computer networking? Computer Networking is the interconnection of computing devices, such as computers, servers, and IoT devices, that communicate with each other to share data and resources. Computer networking is widely used in schools, hospitals, banks, colleges and the IT sector.

What are the types of computer networking that are covered in network basics? Computer networking has four main types:-

Local Area Networks or LAN – It is a private network that connects computers, devices, and servers within a small, limited geographic area, such as a home, office, or single building and offers high-speed data transfer rates, private ownership that is usually managed by one person or organization and components that consist of devices, cables, network switches and routers.

Wide Area Networks or WAN – It is a large-scale computer network spanning broad geographical areas such as cities, countries, or continents, connecting multiple smaller local area networks with common technologies including MPLS, SDWAN and Leased lines.

Metropolitan Area Networks or MAN – It is a high-speed computer network that connects multiple local area networks across a city, town, or large campus, typically spanning 5 to 50 kilometres.

Wireless Network – It is a computer network that uses radio waves, infrared, or satellite signals instead of cables to connect devices like laptops, phones and IoT devices. We have 3 types of wireless networks that are wireless LAN (WLAN), Wireless PAN (WPAN), Wireless MAN (WMAN) and Wireless WAN (WWAN).

Basic Networking Concepts Every Beginner Must Know Essential networking basics include IP addresses, DNS, DHCP, gateway, MAC Address, Ports and Protocols.

IP Addresses (Internet Protocol) are a logical, numerical address assigned to a device on a network, used to identify and route data to that device. IPv4 is a 32-bit IP address, whereas IPv6 is a 128-bit address. We also have public and private IP addresses. Public IPs are visible on the internet, and Private IPs are used inside local networks.

Media Access Control (MAC) Address is a unique 48-bit physical address assigned by the manufacturer to the network interface card. It identifies the physical device on a local network.

The Domain Name System (DNS) is used to translate human-readable domain names into computer-readable IP addresses.

DHCP (Dynamic Host Configuration Protocol) is a dynamic IP address that is automatically assigned, subnet masks, and default gateways to devices, preventing manual configuration.

Gateway is the router address that connects your local network to the wider internet.

Ports are the numerical identifiers that allow a single IP address to support multiple services

Protocols are the standard rules for communication. The types of protocols are HTTP/HTTPS, TCP/IP, UDP, SSL/TLS, SFTP/SSH, DNS, FTP and SNMP, etc.

Understanding the OSI Model (Layer by Layer) OSI Model stands for Open System Interconnection, which divides the communication process into seven distinct layers, each responsible for specific functions related to data transmission and network communication.

Layer 1- Application layer.- In this layer, we get the user interface, where apps like web browsers or email clients connect to the network.

Layer 2- Presentation layer – This layer translates, encrypts, and compresses data so the application layer can understand it.

Layer 3- Session Layer – This layer manages sessions or connections between computers, opening, closing and managing dialogues.

Layer 4 – Transport Layer – This layer handles end-to-end communication, ensuring data arrives, often using protocols like TCP or UDP.

Layer 5 – Network Layer – This layer decides the best physical path for data using IP addresses to send packets across different networks.

Layer 6 – Data Link Layer – This layer prepares data for the physical network, handling MAC addresses and node-to-node transfer.

Layer 7 – Physical Layer – This layer transmits raw bits (0 &1) over physical hardware, such as cables, connectors, or Wifi.

The OSI model is important because it standardises networking, allowing diverse, multi-vendor systems to communicate seamlessly using a 7-layer framework.

TCP/IP Model Overview TCP/IP Model is an integrated four-layer model, standardized framework that defines how data is transmitted over networks and the internet, acting as the foundational language for communication between devices.

The Four Layers of the TCP/IP Model are The Application Layer is the computer networking layer where data is generated and handled, directly interacting with applications. It includes protocols like HTTP, FTP, SMTP, and DNS.

The Transport Layer is a layer that manages end-to-end communication, ensuring data integrity through error control and sequencing. It uses TCP or UDP.

The Internet Layer is the layer that is responsible for logical addressing and routing packets across different networks.

The Network Access layer is the layer that handles physical hardware, MAC addresses, and formats data for the specific physical medium.

Networking Devices you must learn A router is a networking device that connects multiple networks, such as your home network and the internet and acts as a traffic director, directing data packets to their proper destinations.

A switch is a hardware device that connects, disconnects, or redirects electrical currents or data packets.

A firewall is a network security system that acts as a barrier between trusted internal networks and untrusted external networks, monitoring and controlling traffic based on security rules.

An Access Point is a networking device that creates a wireless local area network, typically in an office or large building, by acting as a bridge between wired Ethernet cables and wireless devices.

A modem is a networking device that acts as a bridge between your home network and your internet service provider.

There are also essential networking skills for beginners to learn, that are subnetting basics, troubleshooting commands and network security basics.

Best Networking Certifications for Beginners An entry-level networking certification is CCNA, which stands for Cisco Certified Network Associate. It is the best networking course for beginners that covers IP connectivity, network access and IP services, designed for roles like network engineers and administrators.

An Intermediate Level of networking certifications is CCNP, which stands for Cisco Certified Network Professionals, which has two streams: Enterprise and Security. Candidate can choose according to their interest.

The CCNP Enterprise networking certification covers advanced networking technologies, including dual-stack architecture, virtualization, infrastructure, network assurance, security and automation.

The CCNP Security networking certification covers advanced security technologies, including network, cloud, and content security, endpoint protection, secure network access, and VPN.

An Expert-level networking certification is CCIE, which stands for Cisco Certified Internetwork Expert, which has multiple available tracks – CCIE Enterprise Infrastructure, CCIE Enterprise Wireless, CCIE Data Centre, CCIE Security, CCIE Service Provider, CCIE Collaboration, and CCIE Automation.

Globeclue is providing the networking course training online for beginners, in which they cover the basics of computer networking to an advanced level, such as CCNA, CCNP, Fortinet Firewall, Palo Alto Firewall, SDWAN and CCIE, etc., and they are also providing CCNA notes with practicals, which include networking concepts with labs that are designed to be easy to understand.